Positioning devices incorporating GPS antennas are well known. These devices usually include a single internal antenna which is used for all position measurements. Such a positioning device is described in the commonly assigned application published as US 20060100816, the contents of which are incorporated by reference herein.
Alternatively, a single external antenna may be connected to the device, giving substantially similar capabilities. Some devices use both an internal and an external antenna. These devices generally use the external antenna when it is connected to the device, and the internal antenna when no external antenna is connected. Other devices use switching mechanisms for switching between internal and external antennas. For example, U.S. Pat. No. 6,563,458 describes a GPS receiver with an internal antenna and an external antenna. The receiver switches between the internal antenna and the external antenna based on whether an acceptable signal is available from the internal antenna.
However, prior positioning devices fail to provide for selection of GPS antennas in a way which reflects the manner of use of such devices. This results in inconvenience and inaccuracies in positions measured.